Felice gilardini



FrGILARDINI.

TANNING LEATHER FOR BELTS.

APPLICATION FILED MAY 21.1918.

Patented Nov. 11, 1919.

FELIGE GILARDINI, OF T'UBIN, ITALY.

TANNING LEATHER FOR BELTS.

Specification of Letters Patent.

Patented Nov. 11, 1919.

Application filed May 21, 1918. Serial No. 235,879.

To all whom it may concern:

Be it known that I, FELICE GILARDINI, a subject of the King of Italy, of5 via Giannone, Turin, in the Kingdom of Italy, have invented certainnew and useful Improvements in Tanning Leather for Belts; and I dohereby declare the following to be a full, clear, and exact descriptionof the invention, such as will enable others skilled in the art to whichit appertains to make and use the same, reference being had to theaccompanying drawings, and to letters or figures of reference markedthereon, which form a part of this specification.

This invention has for its object certain new and useful improvements inthe process for tanning leather for belts forming the object of mypatent application filed April 6, 1918, Serial No. 227,051, (when thetanning apparatus forming the object of my patent application filedApril 6, 1918, Serial No. 227,050, is not used), by which a greateconomy is obtained.

According to the process described in my said patent application, it wasnecessary to use a great number of grates, as each skin had to bepressed between a pair ofgrates during the whole tanning process and thefollowing operations. This was necessary in order to prevent the tanliquor acting on the compressed skin sections, which, if not suitablyprotected, would become swollen after soaking.

According to this improved process, the grates are dispensed with, as Ifound how to prevent any action of the tan liquor on the compressedunprepared sections, without using any protecting means.

Said improvements consist in placing the perfectly stretched skinsbetween two dies of a press, preferably a hydraulic press, provided witha plurality of openings (as the grates employed in the process formingthe object of my patent application Serial No. 227,050), the form andsize of which correspond to the skin sections to be treated. The diesare heated and pressed strongly upon the hide or skin while this latteris stretched until the compressed sections are reduced to a thin andexceedingly compact sheet; the

hide is then removed from the press and placed into the tanning pit freefrom any protecting means. The tan llquor, as the practice hasdemonstrated, has no effect on the compressed sections, while itpenetrates the not compressed ones. This im ortant result is obtainedowing to the fact t at the pressure is elfected under heating, so thatthe compressed hide sections are thoroughly drled. A still better resultmay be obtained by spreading on the press dies an adhesive orimpermeable substance, which, during the pressingoperation, effectedunder heating or not, penetrates the superficial layer of the compressedskin, so that this latter will not be affected at all during the tanningoperat1on.

An important economical advantage may be obtained in this process, evenwithout any heating operation, by using thin metal plates provided withopenings corresponding to the skin sections to be treated. In this case,the skin is first strongly pressed between the press dies in order tocompress to the highest degree the hide sections not to be treated; thenthe dies are removed and a thin metal plate, for instance a copperplate, is applied to each side of the skin, which latter, thus coated,is again pressed between the dies and then brought into the tanningpits.

A further modified form of this belting tanning process consists inconstructing the said grates of a particular type of electricallyheating them, in order to maintain the compressed sections of the skinat a certain temperature even during the tanningbath. The grates,provided for the purpose of maintaining the heat on the compressed skinsections, will also heat the tanning solution acting on the sections tobe treated.

In the annexed drawings is shown, by Way of example, a constructionalform of the special grates and metallic protecting plates abovedescribed.

Figure l is a cross section of a grate pair of the type used accordingto the process of my patent application filed 1918.

Fig. 2 is a plan thereof.

Fig. 3 is a section of the hide provided with the protecting copperplates and ready for the tanning bath.

, Figs. 4 and 5 are an external view and a cross section respectively,of an electrically heated grate pair inclosing the hide.

As it appears from Fig. 3 of the drawing, the pair of thin copper plates1, provided with openings corresponding to the sections? to be tanned,are stroi'igly pressed on the compressedsections 2, by means of thepress as above described. If necessary, the plates will be provided withsmall points I to secure them on the hide.

The electrically heated grates illustrated in Figs. and are in theirouter form similar to the ordinary grates described in my patentapplication filed April 6, 1918, Serial No. 227,050, and illustrated inFigs. 1

- and 2 and are'provided with bolts 4:, which :-'are tightened whilethehide is stretched, be-

fore carrying it. under the press and then further tightened while thegreatest pressure is produced by'means of the press.

Each of said rates is rovided with a 'tube pair 5, projectingjfrom' thetan liquor surface in the pits, through which the wires of the electriccurrent are caused to pass.

From said Figs. 4: and 5 it is evident how the windings producing theheating of the plates through electric resistance are arranged.

Evidently the electric heating could be produced by any other knownmeans. The tan liquor acts on the'sections'3 to be treated through theholes 6 of the grates. Owing ments, and subjecting the hide to a tanning solution.

' 2. The method of manufacturing leather which comprises compressing andheating the unprepared hide in spots, removing the pressure therefrom,and subjecting the hide to a tanning solution.

3. The method of manufacturing leather which comprises stretching theunprepared hide, pressing and heating the stretched hide in spots, andtanning the hide.

4:. The method of manufacturing leather which comprises stretching theunprepared hide, pressing and heatin the stretched hide in spots, andtanning the unpressed and un heated portions of the hide.

5. The method of manufacturing leather which comprises applying underpressure, an impermeable substance in spots to the unprepared hide,heating the spots, and tanning the untreated portions of the hide.

6. The method of manufacturing leather which comprises applying to partsof the unprepared hide, a coating insoluble in a tanning solution,subjecting the coated parts to pressure, and subjecting the hide to atanning solution.

7. The method of manufacturing leather which comprises applying to partsof the unprepared hide a coating insoluble in a tanning solution,subjecting the coated parts to heat and pressure, and subjecting thehide to a tanning solution.

8. The method of manufacturing leather which comprises applying anadhesive to the unprepared hide in spots, heating and pressing theadhesive onto the hide, and subjecting the hide to a tanning solution.

In testimony that I claim the foregoing as my invention, I have signedmy name.

FELICE GILARDIN I Copies of this patent may be obtained for five centseach, by addressing the Commissioner of Patents, Washington, I). C.

